Abstract: A display memory control system is disclosed which is associated with a display system for displaying and outputting character data, graphic data and the like. In the event of displaying images on a display, a system (host computer) writes one screen of display data in one of two VRAMs. The display data are transferred to the display and to the other VRAM to be stored therein. Upon completion of the storage in the other VRAM, the display data stored therein are read out to appear on the display. To update the display data, the system makes a write access to the one VRAM within a period of time other than one for which the transfer of video data is effected from the one VRAM to the other VRAM. This increases the period of time within which the one VRAM is accessible by the system and, thereby, enhances high speed data processing and display of high resolution images on the display with a desirable quality.